Prognostic implications of the intrinsic molecular subtypes in male breast cancer.

PURPOSE: Intrinsic molecular subtyping has been widely used in female breast cancer, and it has proven its significance. In this article, we aimed to study the intrinsic subtypes of male breast cancer (MBC) in correlation with clinicopathological features.

METHODS: We retrospectively identified 130 MBC cases from 2004 to 2013. Intrinsic molecular subtypes were determined by immunohistochemistry (IHC).

RESULTS: From a total of 130 MBC cases, 45.4% of tumors were luminal A subtype, 44.6% were luminal B, 5% were HER2 positive and 5% were triple negative tumors. There were statistically significant differences between different IHC intrinsic subtypes regarding tumor size (p=0.001), estrogen receptor (ER) status (p=0.001), progesterone receptor (PR) status (p=0.001), HER2 status (p=0.001) and Ki67 proliferation index (p=0.001).

CONCLUSION: The distribution of breast cancer intrinsic subtypes in males is different compared to its female counterpart; however, they don't seem to give the same prognostic value.